1. Field of the Invention
The present invention relates to an image forming apparatus and, more specifically, to an image forming apparatus having a print server function for managing image data held by other apparatuses connected to a network.
2. Description of the Background Art
Recently, a network system including a terminal such as a PC (Personal Computer) and an image forming apparatus such as a printer, a printer-copier, or an MFP (Multifunction Peripheral) communicable with such a terminal through a network has come to be widely used.
In such a network system, the terminal outputs to the image forming apparatus a print instruction for instructing printing of print data such as an image. Upon receiving the print instruction, the image forming apparatus prints the print data on a sheet of paper in accordance with the print instruction.
In a conventionally well-known network system including an image forming apparatus, it is possible for a user to designate an image forming apparatus as a destination, when he/she operates the terminal to output the print instruction. By doing so, it becomes possible for the user to have the printing process done by the desired image forming apparatus and to confirm the resulting print.
Japanese Patent Laying-Open No. 2000-181653 (hereinafter referred to as “'653 application”) discloses a technique related to the network system including image forming apparatuses. The network system described in '653 application includes, in addition to the image forming apparatuses such as a printer and the terminal, a server that provides a service of automatically determining a destination of print output.
In the network system described in '653 application, a user of the terminal does not designate any image forming apparatus as the destination of print instruction. The terminal transmits the print instruction to the server. Receiving the print instruction, the server determines to which image forming apparatus the print instruction should be transmitted, and transmits the print instruction to the determined image forming apparatus. Receiving the print instruction, the image forming apparatus executes the printing process.
Though hardware reliability has been much improved recently, there is always a risk of server operation failure. In the system described in '653 application, printing as described above is impossible without a server and, in addition, if the server should fail, any process related to printing becomes impossible in the system as a whole. In consideration of such a situation, the system described in '653 application includes two or more servers as prerequisite, and according to the disclosure, if one server should fail, another server is determined to be a substitute.
According to the technique described in '653 application, however, the system requires at least one dedicated print server. Without such a server, the system cannot realize the printing function. Further, at least one additional apparatus must be present, to serve as a substitute print server. Preparation of a substitute print server is disadvantageous in view of cost. Therefore, construction of a system such as described in '653 application including a plurality of image forming apparatuses with reduced burden on system construction has been desired.
At present, an image forming apparatus having a function of storing printed images to allow filing by the user has come to be popular. Generally, such a filing process involves an operation of displaying file names stored in the apparatus on an operation panel and selecting a desired file therefrom. If there is a plurality of image forming apparatuses each having the filing function in a network system, it follows that different images are stored in different image forming apparatuses. If a user wishes to print a certain image data, he/she must first search for the image forming apparatus that stores the image data.
The prior art including the technique described in '653 application cannot solve such a problem.